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Ned at 12:35 PM on 23 March 2010What CO2 level would cause the Greenland ice sheet to collapse?
I wrote: ... we still don't know convincingly where the water came from! To clarify, obviously we know the water came from melting ice. But at least as of a couple of years ago people were still arguing whether that ice was in the Antarctic, North America/northern Europe, or both. -
Ned at 12:28 PM on 23 March 2010What CO2 level would cause the Greenland ice sheet to collapse?
HR writes: Quick question. What do you mean by completely collaspe. How fast, exactly, can an ice sheet disappear? That's a good question, and I wish we knew the answer to that. I have generally been a bit skeptical about some of the hypothesized dynamics involved in "rapid" (century-scale) collapse of large ice sheets, even ones that are grounded below sea level. Greenland in particular is largely surrounded by mountains that would seem to give it a bit more structural support. On the other hand, if you want to lie awake worrying at night, think about meltwater pulse 1a. Sea levels rose on the order of 7-10m per century for a couple of centuries ... and we still don't know convincingly where the water came from! Until we have a better picture of how exactly the Laurentian and Fennoscandian ice sheets collapsed, and whether MWP1A was purely northern hemispheric or there was an Antarctic contribution, I think there's good cause to be concerned about Greenland and the WAIS. The series of meltwater pulses between the LGM and Younger Dryas would be high on my personal list of climate science topics that are in desperate need of more research. -
ProfMandia at 12:09 PM on 23 March 2010What CO2 level would cause the Greenland ice sheet to collapse?
Nice post, John. For those of you in the US, this is a nice page that illustrates sea level rise in coastal cities. Very scary. http://www.architecture2030.org/current_situation/cutting_edge.htmlResponse: Thanks for that link. I've added it to the list of links relevant to sea level predictions. -
Jim Eager at 12:09 PM on 23 March 2010What CO2 level would cause the Greenland ice sheet to collapse?
"Because it sounds like a very sudden, violent process the way you phrase it." Maybe because it would be, compared to how long we used to think it would take to melt large ice sheets like Greenland and West Antarctica. And as John replied, the fact that large portions of the Greenland ice cap and most of the West Antarctic ice sheet are grounded below sea level will allow intrusion of warm sea water beneath the ice, not only lubricating it, but also melting the ice from below. Moreover, it's a process that will continue well beyond 2100, so talk of just building higher dikes and sea walls to deal with a 1-2 meter rise is sheer nonsense. Oh, and remember, those dikes would have to be run up both banks of every river to the new, higher tidal point, mind you. -
HumanityRules at 12:05 PM on 23 March 2010What CO2 level would cause the Greenland ice sheet to collapse?
This Stone paper seems to model greatest mass loss from the north of the continent at CO2 of 400ppm. A recent Howat paper suggests up to 75% of present day mass loss is from the SE of the continent. http://www.agu.org/pubs/crossref/2008/2008GL034496.shtml Does this apparent inconsistency matter? -
HumanityRules at 11:19 AM on 23 March 2010What CO2 level would cause the Greenland ice sheet to collapse?
Quick question. What do you mean by completely collaspe. Do you mean slowly melt? Because it sounds like a very sudden, violent process the way you phrase it.Response: There are two main contributors to ice mass loss from the Greenland ice sheet: melting ice and increased discharge as glaciers are sliding faster into the ocean. Part of the reason why Greenland and West Antarctica are losing ice mass faster than East Antarctica is because part of the Greenland and West Antarctic ice sheets are sitting on bedrock that is underwater - warming oceans speeds up the slide of glaciers that calve into the ocean.
I wouldn't characterise it as a sudden, violent process. I'd characterise it more like pushing a huge, heavy boulder from the top of a hill. It's difficult at first and moves slowly. But then you reach a tipping point where it's momentum starts to carry it down the hill and then there's no stopping it. -
HumanityRules at 11:02 AM on 23 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Sorry WUWT not CA -
canbanjo at 10:55 AM on 23 March 2010What CO2 level would cause the Greenland ice sheet to collapse?
Hi does this alter the sea level rise predictions this century? ThanksResponse: As far as I can tell, it's broadly consistent with the several papers that predict around 1 to 2 metres sea level rise by 2100. But this paper takes a longer view, looking at the impact over 400 years. -
Ned at 10:44 AM on 23 March 2010What CO2 level would cause the Greenland ice sheet to collapse?
Nice post, John. GRACE is really turning out to be one of the best investments of NASA's earth system science program. Your figure 4 is noteworthy. Emissions in the mid-2000s really were on an unsustainable trajectory. Presumably the economic downturn has dropped the line back down a bit, but as the global economy picks up steam again we may head back up towards that ugly BAU line. Melting Greenland is one of those things that will probably take a long time to accomplish but one it starts it will be hard to stop.Response: Hansen describes it well in 'Storms of my Grandchildren'. The Greenland (and Antarctic) ice sheets have great inertia. This means it takes a long time before they start moving. So early on, we think the massive inertia of the ice sheets is our friend. But once the ice sheets start moving and particularly when they reach the tipping point where collapse is inevitable, it's not like we can lassoo a rope over them and hold them back. At this point, the inertia is revealed to be not our friend but our enemy. -
HumanityRules at 10:28 AM on 23 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Svalgaard seems like a perfectly good solar scientist. I was reading many of his posting on CA yesterday because I was going over the ACRIM gap debate again. He seems fairly independently minded, dry, witty and intelligent. I'd agree with 51.Arjan description of the guy. I was wondering whether he is generally seen as a denier because I find him hard to label. -
Leo G at 08:36 AM on 23 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Dhozzer - K, will try to be more accurate - "world leading scientists in their disciplines" This too me of course includes Gavin, Jim, Ray L. Tammy, etc. Yes Doug, solar is one of the things we offer, but just being over the border a bit from you, we find the sale hard. For a lot of people, to long of a RFI. But at least in Vancouver propoer now, any new construction must rough-in for solar panels, so things are getting there. -
dhogaza at 08:26 AM on 23 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
actually Dr. Svalgaard is a highly respected solar scientist.
Saying "he's not one of the world's leading scientists" isn't the same as saying "he's not respected", OK? -
Ned at 07:45 AM on 23 March 2010We're heading into an ice age
N/A writes: I do not know. I only see it as an important question to answer and have yet to see a satisfactory answer. Nothing wrong with that. Spend some time browsing through the pages on this site -- there is a lot of information, and a lot of very careful discussion of the current peer-reviewed literature. A number of the commenters here are scientists working either within climate science or in related fields ... they can provide a very valuable perspective, too. -
Ned at 07:35 AM on 23 March 2010The 5 characteristics of scientific denialism
Unlike hard science, climate science has no expectation that anything is reproducible. Actually, lots of research in climate science is reproducible. You can look at the delta O18 records from ice cores in Greenland and in Antarctica, and they match up quite nicely. The Clear Climate Code project has reproduced the results of GISTEMP using their own software operating on the same input data. Events like the PETM or the Younger Dryas show up in all kinds of different paleoclimate studies. Trends in CO2 concentration at stations ranging from the Arctic to the tropics are comparable. There are small differences among the UAH, RSS, GISTEMP, HADCRU, and NOAA global temperature data sets, but they generally match up pretty closely. And one could go on and on... I'm not sure where you get the idea that nothing is reproducible. Lots of stuff gets reproduced, in fact almost everything out there is being done by at least two groups. -
oracle2world at 07:08 AM on 23 March 2010The 5 characteristics of scientific denialism
And #2 ... when the AGW evidence gets sorted into the good, the bad, and the ugly ... AGW's credibility would be vastly improved. -
oracle2world at 07:06 AM on 23 March 2010The 5 characteristics of scientific denialism
I thought #17 was about climate change true-believers for a moment. Discoverers make their claims directly to the popular media, rather than to fellow scientists. The claimed effect appears so weak that observers can hardly distinguish it from noise. No amount of further work increases the signal. Anecdotal evidence is used to back up the claim. But I digress. The "Impossible expectations of what research can deliver." was most interesting to me. Unlike hard science, climate science has no expectation that anything is reproducible. The density of water is the same here as in Russia (there is consensus on this I believe). But the earth undergoes constant change that doesn't repeat. The day is slowing down, meteor strikes, radioactive elements decaying in the crust, the moon receding every year, continents drift, etc. So from the get-go, climate science is never going to meet expectations. Especially compared to hard science. AGW depends on about a dozen assumptions, some of which are very strong (China and India are not going to play ball), to some that are very weak (warm weather is universally bad). That secondhand smoke example? The NCI estimates 3,000 lung deaths per year due to secondhand smoke. It might even be true. Within the limits of what can be estimated, that is as good as it gets. Over 1,000 people die in highway accidents each MONTH in the US. That is not an estimate, actual numbers. In terms of risk mitigation, highway safety probably deserves 10 times the money spent compared to secondhand smoke. AGW has some hard numbers, CO2 rising, sunspot activity going back hundreds of years, recent satellite data ... and estimates like tree ring proxies, surface temps from ground stations, all the way to complete WAGs a hundred years out. They are not the same and no one in AGW appears to be especially troubled by it. And no matter how solid a theory is, there is no guarantee it won't be found lacking. Gamma ray bursts are a prime example. Energetic, and just HAD to be within the Milky Way, otherwise basic laws of physics would be violated. The key assumption was that the gamma radiation was uniformly radiated. That assumption turned out to be false. Science is replete with stuff like this. The key assumption in AGW is that CO2 determines global temperatures. Particularly CO2 emitted by fossil fuels. Within limits of climate research, this is really hard to pin down. Maybe impossible. It doesn't appear that CO2 was a driver at times in the past, so folks would like to understand what the differences are today that would make it so. Soooooooooooooooooooooo, great article. Since your website got hacked, figure you are now in the big leagues. -
scaddenp at 07:05 AM on 23 March 2010We're heading into an ice age
I hate to be reiterating an old point but its all about rate. The transition into and out of ice age is extremely slow by human terms. (around 10,000 years). The rate of warming we are creating is by comparison very fast. Rates of change that overwhelm species capacity to adapt are the danger. Also, an ice age hardly kills most of the life on the planet. We have been in and out of ice ages right through quaternary period. They affect temperate zones mostly. -
Doug Bostrom at 06:37 AM on 23 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Leo G at 06:22 AM on 23 March, 2010 I do my part by installing high efficiency heating boilers/systems for my customers. I don't know the application space of your customers and I have about 30 seconds available so I'll just put in a blind plug for solar DHW systems. I hope they're on your menu, check 'em out! 10x efficiency dollar/watt over PV, low hanging fruit. -
Leo G at 06:22 AM on 23 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Dhozzer - actually Dr. Svalgaard is a highly respected solar scientist. He was the one on the NASA committee that predicted the low of cycle 24, which all the others on same committee had wrong. And yes, I know that Williss is an amuater, but still, he did go after Goddard quite hard in said post. Actually, there are quite a few scientists such as Paul Dennis (who took to task the assumption that a post on clam shell dating was accurate), Jeff L, a geologist, who right now is trying to educate some on plate tectonics, etc. who post on skeptic blogs. As for Dr. Svalgaard, he just doesn't think that CO2 is going to cause all of those positive feedbacks. Not everyone who posts against AGW is a denier. Most of us agree on the warming, just not the consequences/pro forcings/calamities etc. I do my part by installing high efficiency heating boilers/systems for my customers. I just haven't been convinced yet that the world is going to hell in a handbasket from CO2. But I do keep a very open mind, and always read here, RC, OM and other pro sites, because in the end, I do understand that opinion does not matter, just the data and the facts. Now if I had the education to actually be able to analyze the data, then maybe I would be completely off the fence, and taking a trip down under to buy John a beer or two. :) -
aj1983 at 06:13 AM on 23 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Dr. Svalgaard usually only corrects things he knows that are incorrect. He does not seem to take any side in the global warming debate (you will sometimes see him refuting solar variability theories and the influence on climate if based on bullsh*t though.) He does however try to lecture people about solar physics at the solarcycle24 blog, which are often interesting comments. I respect him for that. He also has a lot of information on his website: http://www.leif.org/research/ -
dhogaza at 04:59 AM on 23 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
But for me, what gives me shivers, is to be able to get answers for my silly questions, both pro and con, from some of the worlds leading scientists! Way to Kewl!
Before you get too excited, I hope you know that Willis is no scientists, and Svalgard is not one of the world's leading scientists ... Though at least he's done some research. Actually, i think he's pretty much the only scientist who routinely posts at WUWT, and it's mostly to tell people they're wrong (it's hard to understand his brand of skepticism, actually). -
Leo G at 04:57 AM on 23 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Oh PS - if you want to see warmers/skeptics and MOR's having some real good discussions right now on ststs, check out Lucia's Blackboard. Very much like this site, in that most of the time, the posters are civil, and trying to show thier view with logic and data. I don't understand much of it, but it sure is great to follow a real scientific discussion in the blog sphere. -
Leo G at 04:54 AM on 23 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Steve L @ 41 - I know most of you people hate this site, but if you want an example of skeptics "attacking" one another, just check out this post - http://wattsupwiththat.com/2010/03/08/nsidc-reports-that-antarctica-is-cooling-and-sea-ice-is-increasing/. It ties in nicely to what John has posted here. Willis, Dr. Svalgard, etc. pretty much go after Goddard quite hard. Also, on another recent post about the Iceland volcanoe, a few geologists are trying to "help" certain skeptics, get their geology correct. To be honest, I cruise both pro and con sites every day, and find that there is less of a choir on the con sites. Now maybe that is because there happens to be more lay people on skeptic sites that have heads full of crap trivia and the scientists try to show them the real data, or maybe it is just the way of the skeptic side, that all science must be challenged. Don't really know. But for me, what gives me shivers, is to be able to get answers for my silly questions, both pro and con, from some of the worlds leading scientists! Way to Kewl! -
We're heading into an ice age
"If you're that concerned about an impending ice age," Really, I am not. My point is that it is possible warming will be good if it prevents an ice age. We seem to be in agreement that CO2 is preventing an ice age. We differ if the CO2 is good or bad. Butr I do not know. I only see it as an important question to answer and have yet to see a satisfactory answer. -
We're heading into an ice age
Well that makes your climate models easy. Are you familiar with the phrase "Dead Certain." Warmer may be inconvenient. Ice will kill most of the life on the planet. I think we should plan for every possible future and not pick only the ones we want to "solve." By the way - how do I get the nam "N/A" and how do I change it? I am having some degree of trouble here. -
Peter Hogarth at 19:58 PM on 22 March 2010Visual depictions of Sea Level Rise
zinfan94 at 05:05 AM on 22 March, 2010 There are of course uncertainties in both the ice melt and the steric contributions, and the fact that these components account for around "85%" of sea level rise, and this is regarded as "within the error bars" indicates that the numbers you mention are reasonable. I have also seen a number of papers indicating a decreased contribution to sea level from land run-off, as more of the river systems are dammed, and more water is used for irrigation etc. I'll look for some global estimates of this. The general view seems to be that Ice melt contributions are going to increasingly dominate sea level budget. -
Jeff Freymueller at 17:22 PM on 22 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
#40 HUmanityRules: "The reality is that the people who don't seem to be able to allow any competing arguments or uncertainty in the science are those that support the 'IPCC concensus'." Nonsense. Science is all about competing arguments. If you want to see competing arguments hashed out, try going to a scientific conference some time. And I guessed you missed the arguments that the IPCC seriously underestimated future sea level rise (by assuming no contribution from melting glaciers). Seriously, there are so many counterexamples to your claim, and as Ned posted in #42 most if not all of what is now the consensus view started out as a hotly contested argument about competing ideas. -
James Wight at 16:38 PM on 22 March 2010Why does CO2 lag temperature?
In 2008, the Antarctic ice core record was extended back to 800,000 years ago using the bottom 200 m of the EPICA Dome C ice core. It shows a similar relationship between CO2 and temperature as the Vostok record does. -
climateresponse at 16:22 PM on 22 March 2010Empirical evidence that humans are causing global warming
Nobody reads peer reviewed science literature except for other scientists. So then, whose fault is when the average person doesn't have the information. Theirs, for behaving like they always have and you should have expected them to, or yours for waiting this long to spell it out for them. For years all we've heard is politicians telling us about global warming and climate change, but not giving us the evidence. Just because some slick talker in a suit says something is true, doesn't mean it is. If that were the case then there wouldn't be so many of them saying so many different things. If you want people to believe you then it is your responsibility to give them reason to. Otherwise you have no right to complain. -
Marcus at 15:25 PM on 22 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
According to This Poll The majority of Australians still believe that CO2 is a Greenhouse gas, is being generated by man-made activity & will be catastrophic if not dealt with soon. I've no doubt that I could find similar polls for the UK & most of mainland Europe-but apparently a single poll in the US is more "proof" than all these other polls from across the globe! -
Ned at 13:19 PM on 22 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Not sure what polls of US public opinion have to do with science. Apparently, according to recent polls, only 39% of Americans accept the theory of evolution. But we're not about to give up on all the biological sciences (I hope) just because a large segment of the general public in one country is misinformed. The same applies to climate science. -
1077 at 13:05 PM on 22 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Hacking isn't any better than armed insurrection. Despicable, not enduring, used by idiots, condemned by history (see the "great" revolution of 1917. Common sense however does matter, eventhough you AGW supporters consider yourselves above it. You are wrong. Not as wrong as hackers but still wrong: Poll: Americans Least Worried About Global Warming Americans rank global warming dead last among eight environmental issues to be very worried about, a new Gallup Poll reveals. The percentage of respondents who said they worry “a great deal” about global warming was just 28 percent, down 5 percentage points from last year. The following are eight environmental issues and the percentage of people who said they are very worried are, according to the poll results released on March 16: Pollution of drinking water, 50 percent Pollution of rivers, lakes, and reservoirs, 46 percent Maintenance of the nation’s supply of fresh water for household needs, 45 percent Contamination of soil and water by toxic waste, 44 percent Air pollution, 38 percent The loss of tropical rain forests, 33 percent Extinction of plant and animal species, 31 percent Global warming, 28 percent For all eight issues, Americans are less worried now than they were a year ago, with the percentage drops ranging from 4 points for “maintenance of the nation’s supply of fresh water” to 9 points for “pollution of drinking water” and “the loss of tropical rain forests.” Worry about global warming peaked in 2007, at 41 percent, and stood at 40 percent in 2000. “Americans are now less worried about a series of environmental problems than at any time in the past 20 years,” Gallup observed. “That could be due in part to Americans’ belief that environmental conditions in the U.S. are improving. It also may reflect greater public concern about economic issues, which is usually associated with a drop in environmental concern.” -
HumanityRules at 12:07 PM on 22 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
#41 I was replying to your point in #39 but I'll give #25 a go. We know enough about the climate system to be confident of the role of CO2. vs We know too little about the climate system to experiment with geo-engineering.Response: I'm actually writing a post that tangentially addresses this argument. Not specifically geo-engineering but the notion that high understanding in one area means we must have high understanding in all areas. Or conversely, the notion that if we have poor understanding in one area, it invalides all the areas of high understanding.
But please do keep the proposed AGW contradictions coming, they're interesting to read. -
Ned at 11:29 AM on 22 March 2010We're heading into an ice age
There isn't going to be an ice age in the next 50 or 100 years. If that was your concern, then you can rest easy tonight. And tomorrow you can wake up and start working on the real problem, which is preventing the potential catastrophe caused by too much warming rather than too much cooling. -
Ned at 11:25 AM on 22 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
HR writes: It's been pointed out many times that 'deniers' very often do disagree with each other, often they are each others biggest critics because they have competing theories. Has that been pointed out many times? I'm not sure that it's even true, let alone that it's frequently pointed out. I think John's point in this thread is that skeptical arguments often implicitly contradict each other, but it doesn't follow from this that skeptical persons actually contradict or criticize each other. And in fact, in my experience, it's very rare for this to happen. When was the last time on this blog that a "skeptic" jumped in and disagreed or corrected another "skeptic"? I spend far too much time responding to even rather obviously mistaken claims by RSVP, gallopingcamel, etc. Personally, I would love it if other skeptics would debunk some of their claims too. Unfortunately, that never seems to happen. I think that the reason for this is that most "skeptics" are motivated more by opposition to the consensus view than by any deep investment in any one particular competing view. If someone were really, really convinced by the whole "galactic cosmic rays" argument, you might expect her/him to argue vociferously against AGW, and to argue equally vociferously against other skeptics who claim that the earth isn't warming at all. But you very rarely see that! And I think that's OK, actually. There's nothing wrong with being diffusely skeptical in opposition to a more coherent argument. Let's say that one of your co-workers suddenly can't find a book, and concludes that another co-worker must have stolen it. You could quite reasonably suggest a whole bunch of mutually contradictory hypotheses -- maybe she actually left the book at home, or maybe it's buried under the clutter on her desk, or maybe she forgot that she loaned it to somebody. Obviously those alternative hypotheses can't all be true, but that's OK. But I think we should be clear on the asymmetry here. The consensus view is, and has to be, very coherent about the big picture (though there's lots of disagreement among scientists about the details, something which many skeptics may not fully appreciate). If a British team claims to have detected a slowdown in the North Atlantic thermohaline circulation, and their claim seriously conflicts with other models or data, that's a contradiction that has to be resolved (generally, by examining other data or other analytical methods or whatever). Eventually, it becomes clear who was right and who was wrong, and the "consensus view" expands incrementally to incorporate that improved understanding. In contrast, the skeptical position can tolerate an almost unlimited range of internally contradictory claims. Very occasionally, you will see a higher-information skeptic contradicting a lower-information one, but usually only on a topic that is so far out (e.g., Beck's claims, or Steve Goddard's "CO2 snow at the south pole") as to be generally embarrassing to the skeptic cause. -
Steve L at 10:17 AM on 22 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
HR #40: Anyone can just write things and pretend they're true, but you've been asked for examples (see #25). Rather than provide some solid and specific ones, you state something silly about the IPCC consensus not allowing any uncertainty (even though uncertainty and terms describing it are explicitly defined in IPCC documents). Rather than go on at length, I'll just say that I think you've got it backwards, upside-down, inside-out, and in the mirror, and you'll have to cite some good examples to change my mind. -
HumanityRules at 09:42 AM on 22 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
39.Steve L at 01:42 AM on 22 March, 2010 You seem to have it upside down. The reality is that the people who don't seem to be able to allow any competing arguments or uncertainty in the science are those that support the 'IPCC concensus'. It's this fact that labels (and excludes) those that have something else to say. I don't see that Pielke et al want the label. It's been pointed out many times that 'deniers' very often do disagree with each other, often they are each others biggest critics because they have competing theories. This is the norm for science. It's the moral and political aspects of the climate debate that sets up this goodies vs baddies scenario. -
We're heading into an ice age
How about preventing an ice age in the next 50 years? Or 100? 50,000 wasy our number. I think you are nit picking.Response: Ice ages take thousands of years to develop. If you're that concerned about an impending ice age, just look to northern Canada. If there's a giant ice sheet slowly creeping down the North American continent, then you have reason to be concerned. But if glaciers are retreating worldwide and the Greenland and Antarctic ice sheets are losing ice mass at an accelerating rate, you can relax about the possibility of an upcoming ice age in your lifetime and the lifetime of your children and grandchildren. -
zinfan94 at 05:05 AM on 22 March 2010Visual depictions of Sea Level Rise
Peter Hogarth: It has also now become possible to attempt to “close” the sea level budget, which has components of reported thermal expansion of the volume of water due to increase in accumulated heat energy, and also an increased component from melting ice from land based sources. Again refinements and corrections of recent datasets from GRACE (with GPS) and ARGO resolve previous and relatively recent difficulties, so that the sum of these climate-related contributions (2.85 ± 0.35 mm per year) is now comparable with the altimetry-based sea level rise (3.3 ± 0.4 mm per year) over the 1993 to 2007 period (Cazenave 2010, reporting a consensus of the Ocean Observing Community). Using these datasets it is estimated that around 30% of the observed rate of rise over the satellite altimeter time period is due to ocean thermal expansion and 55% results from accumulated melting land ice. There is evidence that the land ice melt contribution has increased significantly over the past five years. For about five years, the skeptics have argued both that the ice sheets aren't melting quickly, or even melting at all (in the case of Antarctica), while at the same time using Argo data to argue that the OHC has leveled off. I always found this a weird combination of claims, since the data is clear that SLR continues. If the ocean isn't heating, then the ice sheets and glacier would have to melting at an unbelievable rate. Or conversely, if the ice sheets weren't melting, then the ocean heating is just as unbelievably high. The only way to explain SLR is to use a both ice fairly high sheet melt and fairly high ocean heating. No other combination works. Your quote of 30% of SLR due to ocean heating and 55% due to melting land ice, while at the same time claiming these rates are consistent with SLR, is the first I have seen these numbers. But that still leaves us with a couple of problems... Assuming the planet's net energy imbalance isn't changing dramatically (without volcanic or solar changes), and SLR over the last 12 years is roughly the same rate as the last 30 years, then the ocean heating must be relatively constant. If land based melt is increasing dramatically, then the ocean heating rate must be falling dramatically; otherwise the rate of SLR would be increasing. So I am having a bit of a hard time understanding the statement of how land based ice melt is increasing is consistent with the rest of the analysis. It would help if I knew what the likely error band is for the 30% and 55% figures. Is it possible that long term ocean heating would be responsible for 50% instead of 30%, and more recently this has dropped to only 35-40% instead of 30% as this report suggests. I am just having a difficult time figuring out how the rate of ocean heating could swing as much as you seem to be suggesting. To look at it in slightly different way: If land based melt is increasing, then this is bad because we should begin to see even higher rates of SLR as the ice sheets become more and more unstable. But if land based melt is less than 55% as suggested here, then the ocean heating is much higher, which means the planet is heating much faster. As bad as increased ice sheet melt, the idea that the ocean heating is heating fast enough to explain 50% or more of SLR is even scarier. Attributing SLR and proportioning SLR to these two causes is very important. I think Trenberth is right with oft misquoted and misunderstood comment " Its a travesty ..." -
Steve L at 01:42 AM on 22 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
#33 & 34: Let them define themselves then. And they do -- they define themselves by who/what they war against (and who/what they do not!). When I see AGW-deniers attacking the wrong statements of other AGW-deniers, then I'll start thinking that maybe they're interested in truth. -
RSVP at 00:08 AM on 22 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
article states "...how the hacker got in, where they came from..." No details... bummer. -
James Wight at 22:41 PM on 21 March 2010Southern sea ice is increasing
"Goddard commits this error on several occasions." Sorry to nitpick, but your quote at the top was from James Taylor, not Steve Goddard.Response: Please, nitpick away. I've removed the Goddard reference which was a hangover from the original post responding to several Goddard posts at Watts Up With That. -
JMurphy at 22:35 PM on 21 March 2010The 5 characteristics of scientific denialism
PS Both of the trends in the link above (for UAH and GISS) show a rising trend for the last decade, as seen by looking at the data here. And I've just noticed, gallopingcamel, that your link to Watts is for July 2009. Why don't you use something more recent ? -
JMurphy at 22:29 PM on 21 March 2010The 5 characteristics of scientific denialism
gallopingcamel wrote : The second graph (Global Land-Ocean) shows a rising trend over the last decade. The UAH one (Lower Troposphere) shows a falling trend over the same period. http://wattsupwiththat.com/2009/07/03/uah-global-temperature-anomaly-for-june-09-zero/ Am I comparing apples and oranges? You are comparing an insignificant trend to an insignificant trend, because you are only using 10 years, so it is a waste of your and my time. Try it for 30 years, which will be far more significant. However, if you insist that you want to use an insignificant trend over the last decade, have a look at this and see how similar those insignificant trends are : Insignificant 10 yeart trends -
James Wight at 19:57 PM on 21 March 2010Every skeptic argument ever used
I don’t want to create more work for you, but maybe I can suggest some low-hanging fruit that you could tackle. There are several arguments on the full list which you have already discussed in some form on Skeptical Science, but do not have a page of their own. Perhaps you might like to look at adding separate pages for some of the following: • Antarctica is cooling (in a recent post on sea ice) • Southern sea ice is increasing (also in sea ice post) • Mike’s Nature trick to ‘hide the decline’ (on Climategate page) • IPCC overestimate the danger (on IPCC page) • 500 scientists refute the consensus (in an old 2007 post) • Outgoing longwave radiation hasn’t changed (on CO2 effect page) • It’s part of a 1500 year cycle (on natural cycle page) • Mauna Loa is a volcano (on CO2 measurements page) • CO2 emissions do not correlate with CO2 concentration (in a 2009 post) • Models exaggerate projected temperature rise (on models page) • Hansen’s 1988 prediction was wrong (also on models page) The following have been at least briefly mentioned: • Institute of Physics doesn’t support AGW (listed on consensus page) • Springs aren’t advancing (mentioned on evidence for global warming page) • Greenhouse effect does not exist (partially explained on CO2 effect page) • Temperature has fallen while CO2 was rising (discussed in several contexts) • Triton is warming (briefly discussed on other planets page) • Ocean acidification isn’t going to happen (mentioned on positives vs negatives page) • Earth hasn’t warmed as much as expected (alluded to on models page) Again, my suggestion is not intended to create unnecessary work, but is more about gathering together info already on the site into a more obvious location.Response: This is a great idea, many thanks for the suggestion. Think Homer Simpson muttering "mmm... low lying fruit". I've plucked the lowest of the low lying fruit by posting responses to the following skeptic arguments which all will zip into iPhone apps across the world over the next few days (the app updates its own content on a regular basis):- 500 scientists refute the consensus
- Southern sea ice is increasing
- Mike's Nature trick to hide the decline
- CO2 emissions don't correlate with CO2 levels
- Hansen's 1988 prediction
-
quokka at 19:41 PM on 21 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
On the topic of stolen passwords, would it not be advisable to store a one way hash of passwords rather than the cleartext? Even if the site is compromised, the passwords would still be unrecoverable.Response: I may just do that - thanks for the suggestion. Back when life was simpler and climate websites didn't get hacked, clear text passwords didn't seem like such a big deal :-( -
Eric L at 18:37 PM on 21 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Can I issue a retraction of a contradiction? I thought I read somewhere that the first picture for the Mars climate change was taken in 1998, but then I read your site and found it was 1977.Response: The contradiction is still valid but I've updated your comment, changing the date to 1977. -
frankbi at 18:03 PM on 21 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
John Cook: Let me think... well, for one thing I'd like to know which IP address(es) the cyber-attacks came from. Also, what were the exploits being used, and did the cracker(s) try to create any hidden backdoors for future incursions? Thanks for your time! -- frankbiResponse: The IP address of the hacker came from Spain (whether that is the hacker's actual location is another matter, I have had experience before with people spoofing their IP address to hide their location). If you don't mind, I won't go into too much detail into how they did it - don't want to create a roadmap for other hackers (although the security hole they exploited has been secured). -
frankbi at 17:16 PM on 21 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
Shorter HumanityRules: The cyber-attack hasn't been linked to denialists, and even if it has, it's OK anyway for them to attack, because I don't like the label "denialist". -- frankbi -
HumanityRules at 16:47 PM on 21 March 2010Skeptical Science housekeeping: Contradictions, URLs and getting hacked
31.birdbrainscan at 14:12 PM on 21 March, 2010 I agree the unwelcome attention is more evidence of the ethical as well as logical bankruptcy of the denialists. ?Has the hack been linked to denialists? I thought of an analogy for the unscientific denier/alarmist imposed split. Think of this approach applied to politics in general. We have the 'centre ground' represented by the moderates in the main political parties. Pro-market liberals and social conservatives. Outside this 'concensus' we have what might be described as the extremists. Some examples might be religious conservatives, green environmentalist, free market libertarians, leftists and many more. What can we say about an extremists position on issues like taxes, immigration, healthcare and so on. Very little because they all disagree. Does this disagreement say anything about the validity of their position? No, just that we should never have grouped them in the first place.
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